Improvement in lathe-dogs



lith %tti5 HENRY K. WHITE, OE CHELSEA, MASSAGHSETTS.

Letters Patent No. 112,759', dated March14,1871.

IMPROVEMENT IN LATHE-DOGS'.

The Schedule referred to in these Letters Patent and making part of thesame.

turning lathes, it is customary to fasten one end of thestick by forcingit against a mandrel-dog, having radial teeth, that sink into the woodand hold it fast, or cause it to be heldfast between the dog and theback poppet, so that the stick turns with and by the rotating mandrel.

These teeth are very liable to split the wood, especially when the woodis turned down nearly to them;

and e The object of my invention ist'o so construct the clamping-dog asto insure the wood against any liability to split by the action of theteeth; and for this purpose I make or provide the dog-stock with anencompassing-sleeve or tube, which is internallyscrewthreaded ornut-threaded, and. works upon a male thread on the stock, the front endof the tube being made sharp, so that, when fed up into the plane oftheends of the dog-teeth, or slightly projecting beyond them, the saidedgeshall strike into the end of the stick to be turned, thereby holding thematerial, into which the teeth enter, and eieetually preventingit fromsplitting, although the turning-'tool may cut down to the tube.

It is in this sleeve, encompassing or working upon the stock of thelathe-dog, that my improvement c011- sists The drawing represents, inend view and in side and .sectional-elevation, a lathe-dog (for awood-turning lathe) embodying my invention.

a denotes the stock of the dog, having formed on its front end theradial teeth or bits'b, (the points or edges of' which are in a planeright angular to the axis of the stock,) at the'center'of which may be aprojecting spur or point, c.

As the wood is driven against the end of the dog, these teeth enter thewood parallel to or inline with the grain, and tend to split open theend.

cl denotes the sleeve, preferably made with the nutthread e, and workinguponthe screw-thread j', ou the stock.

The front end of the tube has the cutting-edge g, and this edge ispreferably kept in or. just in advance of the plane of the front edgesof the bits or teeth b by a cheek-nut, h.

The end of the wood being driven upon this front edge, as well as uponthe teeth, the grain or fibers of the wood are held together within thering, and prevent any splitting, either withiu or outside the ring,enabling the wood to be turned down even to the ring without injury orliability of the Woodv to break open. n

As the edge of the sleeve wears 0r becomes dull it can be sharpened,and, as' ground down, can be kept up to the proper plane by thescrew-threads and checknut.

A lathe-dog,l having an encompassing-sleeve, the sharpened front edge ofwhich is or may be brought into a plane with the dog-teeth or bits, sothat the edge of the sleeve, as well as the edges of the teeth, enterthe wood, substantially as described.

Witnesses: HENRY K.' WHITE.

FRANols GoULD, S. B. KIDDER.

